Transport spectroscopy of a single atom in a FinFET

Abstract

Current semiconductor devices have been scaled to such dimensions that we need to look at them atomistically to understand their operation for nanoelectronics. At the same time this also brings new opportunities such as electrical access to a single dopant. This paper focusses on the physics of transport through a single n-type dopant in a semiconductor and the gate control of the wavefunction of this atom. Understanding and controlling a dopant's wavefunction in a nanostructure is a key ingredient of Si quantum electronics. In our experimental system we are sensitive to only a single As donor incorporated in the channel of a Si triple-gate transistor and measure the level spectrum and charging energy by means of transport spectroscopy. These levels can be assigned to the dopant, a triangular well at the interface and hybridized combinations of those two. The assignment is based on atomistic modeling of the dopant close to the interface in a tight binding approach. © 2008 IOP Publishing Ltd.